This invention relates to fuel supply systems for small engines in general, and more particularly it is concerned with a fuel supply system for a small engine of the type suitable for use as a power source for a tiller.
In the fuel supply system of this type of small engine, it is well known that a fuel tank is mounted on the underside of a carburetor and connected to a constant level fuel chamber via a fuel drawing pipe so as to draw the fuel in the fuel tank into the constant level fuel chamber to temporarily store same therein, whereby the fuel temporarily stored in the constant level fuel chamber can be ejected into the carburetor through a main nozzle.
No trouble is encountered when this type of engine is used if the fuel tank is in a horizontal position. However, in case this type of engine tilts to a large degree, the following troubles would occur. If the fuel tank is filled with fuel when the engine tilts, the liquid level would be disposed higher than the level of the main nozzle and the fuel would inadvertently flow from the main nozzle to overenrich the fuel-air mixture, with the result that the engine would be rendered inoperative. On the other hand, if the fuel in the tank is very small in quantity when the engine tilts, the fuel could not be drawn by suction and the engine would be rendered inoperative.
This type of small engine is disadvantageous as compared with an engine of the float type in that there are limits to the degree of tilting thereof when in service. When this type of small engine is used as a power source of a tiller, for example, the tiller itself will be limited to the degree of tilting of the engine. The tiller often tilts to a large degree in view of the nature of the work it is required to do, so that the performance of the tiller would be greatly reduced if it is restricted by the degree of tilting of its engine.